Rewire

[sparky999]

Hi there guys started a rewire on weds on a 3 bed bungalow insurance job after whole bungalow got flooded out after the pipes burst. They want to move the Fuseboard from the garage and then into a cupboard.

The new board is Roughly 6 metres aways what shall i do put it through an rcd isolation switch first not done to many long runs of tails as mainly do new builds.

This is wht im up against!

http://i633.photobucket.com/albums/uu58/sparky_011/Photo0026.jpg

http://i633.photobucket.com/albums/uu58/sparky_011/Photo0030.jpg

 

[Andy™]

It will need a switch fuse installed (general rule is over 3mtr needs switch fuse - check with DNO for their requirements). under 17th ed, you shouldn use an RCD main switch, so would need to be taken in SWA or surface/earthed conduit etc

 

[green-hornet]

6 metres is quite a move, you will have to put an isolation switch near the in commer.The problem then arises with descrimination so choose your rcd wisely.

Noticed on the pics it may be wise to order a cut out change from united utilities, some utility companies are now replacing the TNS earthing arrangements to TNC-S, but not all!

The new fuse they put in will at least to some extent improve the earth.

The fuse in that pic I have found to be 60amp but dont quote me lol

 

[batty]

Sparky999

I did a similar job recently although it was a house. I put a wylex 100 amp switch fuse in. I used a bit of 25mm 3 core swa from this into mk metalclad consumer unit in house. In garage I put garage supply unit as not much power was needed in it. At time I put 80 amp fuse in wylex unit but I have found out that 63 amp ones are available. The main fuse is only 60 amp on your job so a 63 amp fuse will be easily adequate. The reason I put 100 amp switchfuse in is so supply could be upgraded if necessary.

Batty

 

[Andy™]

most switch fuses have a standard type fuse, so you can easily add various ratings

 

[sparky999]

cheers guys, there is only an electric shower going in really with any decent size of a load, no cooker as it will be gas, 11 lights and roughly 20 sockets and a immersion heater.

Can you chisle tails in 50mm and more or is tht not aloud, we only have to chisle about 8 inches then run it along in the loft.

 

[sparky999]

Sparky999At time I put 80 amp fuse in wylex unit but I have found out that 63 amp ones are available. The main fuse is only 60 amp on your job so a 63 amp fuse will be easily adequate.

Batty

Any links for that batty might as well have a search for it now.

 

[green-hornet]

you can chase them in more than 50mm, but to be honest batty has the best idea, easier and faster and no need for the isolation to be rcd

 

[Andy™]

If you do chase them in more than 50mm, make sure the wall is still structurally safe!

and remember, if you do put them more than 50mm in.... good chance its less than 50mm from other side

 

[sparky999]

Cheers for your replies guys.

 

[batty]

Any links for that batty might as well have a search for it now.

Switchfuse is 110m cartridge fuse is lfl63 will try to put link.

http://www.electrium.co.uk/Wylex2009.pdf

Page 28 and 29

 

[SLIPSHOD & SLAPDASH]

The new fuse they put in will at least to some extent improve the earth.

Could you explain why ?

 

[green-hornet]

Yes a couple of jobs I have done I have found the old multy strand to be abused over the years with srands missing and even in some cases held to the (lead) part of the cable by wraping around and insulation tape.

Whilst there is a path to earth agreed it is not as sound as it could be.

For example on property I did had a Ze of 0.56 before cutout and 0.28 after.

I would not dare to say every property is the same but that is what I have found in a few cases.